In a development that is could give further hope to climate conservation, scientists have managed to create non-toxic crystals that generate electricity from heat. The new study, led by Emmanuel Guilmeau, CNRS Director of Research at the Laboratoire de Cristallographie et Sciences des Matériaux (CRISMAT), claims that its findings will pave the way for harnessing heat for efficient and safe conversion into electricity via the use of low-cost thermoelectric materials.
The science and other stuff to know
Heat is the most common source of energy waste in any mechanical or industrial process. Despite all of the advances, internal combustion engines still lose 65 percent of the heat energy produced during operation. That is a lot of energy that, according to thermoelectricity laws, has the potential to be converted into electricity.
In the latest study, researchers worked with synthetic copper mineral and subjected it to simple changes that redefined its structure and behavior, giving it the desired properties to easily enable thermoelectricity, according to a press release.
Guilmeau said the novel synthetic material “was composed of copper, manganese, germanium, and sulfur”, and was produced in a rather simple process. “The powders are simply mechanically alloyed by ball-milling to form a precrystallized phase, which is then densified by 600 degrees Celsius. This process can be easily scaled up,” he added.
Guilmeau and his team were focused on finding alternatives to toxic materials like lead, so they experimented with copper-based sulfide minerals, which are abundant and nontoxic. Their experiments with the structures surprised the team itself. “Usually, slightly changing the composition has little effect on the structure in this class of materials,” Guilmeau said. But tiny changes, like replacing a part of manganese with copper, led to major microstructural changes.
While thermoelectric materials have existed and aided the conversion of heat to electricity for a long time, their use has been expensive, both monetarily and environmentally. Despite offering high conversion efficiency, materials like lead and tellurium lead to poisoning and are extremely harmful to the environment.
The new non-toxic materials could prove to be the best of both worlds, converting heat energy more efficiently and with far lesser damage to the environment. They could be extremely beneficial for industrial processes, where heat is an essential source of electric power.
Researchers like Guilmeau have high hopes for the future of these thermoelectric crystals. It goes without saying further testing would follow in the days ahead to check the efficacy of the materials in real-life scenarios, but Guilmeau has no doubt that their findings have led them to “cheaper and nontoxic thermoelectric materials” that could end the need for toxic materials. For the sake of our planet’s health, we sure hope he’s right.